From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38C66C433EA for ; Tue, 28 Jul 2020 20:23:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DBFF2065E for ; Tue, 28 Jul 2020 20:23:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728949AbgG1UXE (ORCPT ); Tue, 28 Jul 2020 16:23:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728437AbgG1UXB (ORCPT ); Tue, 28 Jul 2020 16:23:01 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70245C061794 for ; Tue, 28 Jul 2020 13:23:01 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 303C628EA02 From: Gabriel Krisman Bertazi To: luto@kernel.org, tglx@linutronix.de Cc: keescook@chromium.org, x86@kernel.org, linux-kernel@vger.kernel.org, Gabriel Krisman Bertazi , kernel@collabora.com Subject: [PATCH 5/6] arch: x86: Reclaim TIF_IA32 flag Date: Tue, 28 Jul 2020 16:22:28 -0400 Message-Id: <20200728202229.1195682-6-krisman@collabora.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200728202229.1195682-1-krisman@collabora.com> References: <20200728202229.1195682-1-krisman@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dropping this as a TIF flag is interesting given the pressure over x86 remaining x86 flags, plus considering the current common entry code, reducing arch-specific flags is a good thing. Notice that no path really relies on TIF_IA32 as part of a critical path, therefore the cost of checking another field in thread_info shouldn't be a problem. Signed-off-by: Gabriel Krisman Bertazi --- arch/x86/include/asm/thread_info.h | 4 +--- arch/x86/kernel/process_64.c | 3 --- 2 files changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 698feefd5f5f..aa7d27054a8a 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -99,7 +99,6 @@ struct thread_info { #define TIF_NEED_FPU_LOAD 14 /* load FPU on return to userspace */ #define TIF_NOCPUID 15 /* CPUID is not accessible in userland */ #define TIF_NOTSC 16 /* TSC is not accessible in userland */ -#define TIF_IA32 17 /* IA32 compatibility process */ #define TIF_SLD 18 /* Restore split lock detection on context switch */ #define TIF_MEMDIE 20 /* is terminating due to OOM killer */ #define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */ @@ -129,7 +128,6 @@ struct thread_info { #define _TIF_NEED_FPU_LOAD (1 << TIF_NEED_FPU_LOAD) #define _TIF_NOCPUID (1 << TIF_NOCPUID) #define _TIF_NOTSC (1 << TIF_NOTSC) -#define _TIF_IA32 (1 << TIF_IA32) #define _TIF_SLD (1 << TIF_SLD) #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) #define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP) @@ -245,7 +243,7 @@ extern void arch_setup_new_exec(void); #define arch_setup_new_exec arch_setup_new_exec #endif /* !__ASSEMBLY__ */ -#define TASK_IA32(tsk) test_tsk_thread_flag(tsk, TIF_IA32) +#define TASK_IA32(tsk) (task_thread_info(tsk)->psabi == PSABI_IA32) #define TASK_X32(tsk) test_tsk_thread_flag(tsk, TIF_X32) #endif /* _ASM_X86_THREAD_INFO_H */ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index aea2c03e8a5d..75059c9de829 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -533,7 +533,6 @@ void set_personality_64bit(void) /* Make sure to be in 64bit mode */ current_thread_info()->psabi = PSABI_IA64; - clear_thread_flag(TIF_IA32); clear_thread_flag(TIF_ADDR32); clear_thread_flag(TIF_X32); /* Pretend that this comes from a 64bit execve */ @@ -555,7 +554,6 @@ static void __set_personality_x32(void) { #ifdef CONFIG_X86_X32 current_thread_info()->psabi = PSABI_X32; - clear_thread_flag(TIF_IA32); set_thread_flag(TIF_X32); if (current->mm) current->mm->context.ia32_compat = PSABI_X32; @@ -577,7 +575,6 @@ static void __set_personality_ia32(void) { #ifdef CONFIG_IA32_EMULATION current_thread_info()->psabi = PSABI_IA32; - set_thread_flag(TIF_IA32); clear_thread_flag(TIF_X32); if (current->mm) current->mm->context.ia32_compat = PSABI_IA32; -- 2.27.0